docs: def get_delta(self, branch, turn_from, tick_from, turn_to, tick_to):
          """Get a dictionary describing changes to all graphs.
  
          The keys are graph names. Their values are dictionaries of the graphs'
          attributes' new values, with ``None`` for deleted keys. Also in those graph
          dictionaries are special keys 'node_val' and 'edge_val' describing changes
          to node and edge attributes, and 'nodes' and 'edges' full of booleans
          indicating whether a node or edge exists.
  
          """
          from functools import partial
          if turn_from == turn_to:
              return self.get_turn_delta(branch, turn_from, tick_from, tick_to)
          delta = {}
          graph_objs = self._graph_objs
          if turn_to < turn_from:
              updater = partial(update_backward_window, turn_from, tick_from, turn_to, tick_to)
              gvbranches = self._graph_val_cache.presettings
              nbranches = self._nodes_cache.presettings
              nvbranches = self._node_val_cache.presettings
              ebranches = self._edges_cache.presettings
              evbranches = self._edge_val_cache.presettings
          else:
              updater = partial(update_window, turn_from, tick_from, turn_to, tick_to)
              gvbranches = self._graph_val_cache.settings
              nbranches = self._nodes_cache.settings
              nvbranches = self._node_val_cache.settings
              ebranches = self._edges_cache.settings
              evbranches = self._edge_val_cache.settings
  
          if branch in gvbranches:
              updater(partial(setgraphval, delta), gvbranches[branch])
  
          if branch in nbranches:
              updater(partial(setnode, delta), nbranches[branch])
  
          if branch in nvbranches:
              updater(partial(setnodeval, delta), nvbranches[branch])
  
          if branch in ebranches:
              updater(partial(setedge, delta, lambda g: graph_objs[g].is_multigraph()), ebranches[branch])
  
          if branch in evbranches:
              updater(partial(setedgeval, delta, lambda g: graph_objs[g].is_multigraph()), evbranches[branch])
  
          return delta